LAN and WAN – Definition, properties and differences

If you have been wondering what LAN and WAN mean then you should be warned that after reading this article you will not only know their definition but also their properties and the differences between them so next time you will hear about LAN and WAN you will not see them as just weird alien cryptic letters meant to make you scratch your head and look puzzled.

There are several types of computer network designs or architectures if I can say so, and they are named mostly based on their scope or scale. In the past, there was a need to address each type of network by a certain name, need that wasn’t probably based on a technical requirement. We inherited those names and, as they became widely known, they were left that way. Now, they are still called area networks but keep in mind that their names reflect the scale and scope.

I will also try to cover a few other types of networks but in another article that you can read here. The most widely known are: LAN and WAN and even if you’ve probably used a PAN in the last week, and even used a MAN in the last two days, this doesn’t mean you will never need to know what they actually are.

Back to the subject of this article, I will focus on a few of the particularities of each network type, while in the end I will present the main differences between LAN and WAN and what LAN and WAN mean as terms.

LAN definition and properties

LAN stands for Local Area Network and it interconnects devices in a limited area such as home, school laboratory, college or university campus, office building and occasionally, a LAN will span to a group of close buildings.

This is not a rule, because LAN is pretty flexible when it comes to defining a location for it. For example, you can have several LANs inside a single building, not only a single LAN as present in the first sentence, and one thing that most of the times will happen is that a LAN, mainly in TCP/IP networking ,will be implemented over a single IP subnet.

You can imagine by now that LANs depend on the network media (cables, devices and other physical components) for interconnection of devices and to better understand this concept, I will mention here Ethernet technology which fully supports LAN interconnections.

Ethernet connections for LAN include media wiring like coaxial cable (this was used in the beginning as a method of interconnection for Ethernet) that evolved now-a-days into twisted pair and fiber optic cables used with switches and routers. I also have to mention HUBs used with twisted pair cables that act, in some ways, like a switch (but would not compensate for all the functions and abilities of one). They were preferred because of the low costs but I will not go into more details regarding this, as it is not the focus of this article.

Ethernet technology uses straight through or path cables to connect hosts (computers or other devices with network capable interfaces) to switches, routers or hubs.

Ethernet technology also uses cross over cables to connect network devices of the same kind (for example switch to switch or computer to computer). This method of interconnecting became almost obsolete as current Ethernet implementations on devices support AUTO-MDIX. This is a feature to automatically change the configuration, transparent to the user, so that MDI or MDIX ports detect the needed configuration and applies it to the connection as long as the data rate and duplex settings on the network interface card are set to auto.

LANs support higher data-transfer rates while forcing to cover a smaller geographic area.

LANs can also be build using other technologies than Ethernet, for example ARCNET and Token Ring. However, Ethernet is preferred as technology on LAN, due to its constant development and improvement but Wi-Fi can also be used, if needed.

WAN definition and properties

WAN, as an acronym comes from Wide Area Network and it is exactly what it says, a network that spans over a large physical distance. The World’s largest WAN is, as you may have already figured it out, the Internet.

A collection of dispersed LANs over large distances spread to different locations form a WAN.

Devices like routers interconnect LANs, while also connecting LANs to WANs. Routers can have multiple network interfaces, each of them part of a different network. For example, a router can have an interface connected to a LAN1 (LAN1 is just a name to be differentiated, but in fact is just a LAN), another interface connected to another LAN2 (LAN2 is just a name to be differentiated, but in fact is just a LAN), and a third interface (usually serial interfaces when we talk about WANs) connected to a WAN. So you can see now how a router can connect LANs to WANs and interconnect networks.

WANs are not managed by single organizations or network administrators as individuals for example. We can actually say that it is managed by simultaneous administrations or distributed responsibilities, each section managed under its owner.

WAN technologies include Frame Relay, ATM and X.25 and we can refer to it in a few words by saying that a WAN is a network that spans over a large distance, even better: a telecommunication network that link LANs over metropolitan, regional or national limits by using private or public network transportation service providers, like for example WAN over leased lines.

LAN and WAN differences

People make use of LAN, whether they know it or not, whenever they go home and connect to the Internet WAN via an ISP (Internet Service Provider) and using ISP’s broadband modem.

The ISP provides a configuration to the modem, which also includes an IP address and the computers at home that use LAN private IP address. Using NAT (Network Address Translation) the WAN IP address is used by computers inside the LAN whenever they reach Internet. The whole process is automatic and transparent to the user, we use so many technologies each day when we access Internet that you can’t even imagine. Some of you can stay ignorant, but those of you who can’t, will have to do a lot of research to understand at least a part of what is going on behind for example, sending an email, or watching a video with an Internet Web Browser.

All computers inside home network LAN can communicate directly with each other but in order to access the Internet WAN, they must go through the gateway (and in some cases a few routers) to reach the ISP, which in most cases is a broadband router.

I couldn’t cover everything regarding this subject; I’m just trying to form a bigger picture for you. The amount of information I would have to describe in here to cover everything behind a LAN and a WAN is impossible to finish in an article and I couldn’t even estimate the time need it to do so.

The best way is to get the information you need from here and search for other sources too if it got you interested. I will also write a later article with many more details about LANs, WANs and networking, which might be useful handy in time, so keep an eye on my blog.

I will end this article by presenting in a better structured way (a table) the differences between LAN and WAN, what makes them be what they are, even if I have already mentioned some of the details. The table will cover what LAN and WAN represent but also each network property.

Properties

LAN

WAN

Acronym for

Local Area Network

Wide Area Network

Definition

Small computer network that covers a small geographic area like a home, school, campus, office, or a group of close buildings.

Computer network that spans over a large geographical distance, like communication links that cross metropolitan, regional or national limits.

Speed Estimated

1000 mbps and more

150 mbps and more

Data Transfer rates (Speed)

higher

lower

Spread in the World

Small geographical range(does not need leased lines – does not cross large geographical distances).

Large geographical range spreading mostly across national limits (uses leased lines where needed – crosses large geographical distances like for example oceans and countries).

Implementation costs

Low costs for network media and technicians to design it, low costs tend to get higher if you design it from scratch.

Due to the fact that remote LANs have to be interconnected, the prices can be pretty high, especially with leaded lines. If you use software to interconnect LANs, like VPN technologies it can be cheap but with a higher risk for security, as sending data over such a big network (unmanaged and uncontrolled in some places) like Internet, can be unsafe even when encrypted. You must assume there are a lot of people who would like to get their hands on the info you will try to move through vpn tunnels, for example.

Maintenance costs

Easy to maintain at low costs due to the small coverage area.

Higher maintenance costs due to level of technicians knowledge needed to manage it but also due to the big distance over which the network could be spread and problems that might arise.

Ownership

Owned, controlled and managed by a single person or organization.

Not owned by a single entity, WANs are managed under collective or distributed ownership and management split among different organizations and Service Providers that form the whole network, take for example: the Internet.

Fault Tolerance

Problems occur less frequent because a LAN network will have fewer systems associated with them.

Less fault tolerant due to the fact that a high number of systems depend on the service.

Components

Layer 1 devices – HUBs and Repeaters (mostly mentioned due to historical events but less used today, the only good thing that still keeps some of these devices on the market is the low price).

No, did you read the article?
There are multiple factors that determine this: coverage that can be a house, school, floor, etc; speed which is typically faster than a WAN due to the other mentioned factors and technologies used; ownership; costs; bandwidth; etc.

I’ll also throw in an a simple example for you but I encourage you to come back and ask me if this still doesn’t make it clear for you.
At your home you have a small LAN made of your computer(OWNER: you) and probably a router(OWNER: you) with a modem(OWNER: ISP) from your Internet provider before the router. Your router has two interfaces at least, one for LAN and another for WAN. The LAN is the one connected to your computer so you have your LAN. The WAN would be connected to the modem. The modem in your premises which would be connected to another modem and then to other devices. It gets a bit messy after the modems and between them but I won’t get into details. The thing to know is that the interface of your router that says WAN connects to the “Internet”. This is the WAN. If you had another computer inside your LAN next to yours you could actually test some of the other factors that represent criteria for LANs/WANs like speed for example.